Yarn weight is important in achieving the correct gauge or tension for a particular project and can help with yarn substitution. Most yarns state their weight on the ball band but some may not,this is particularly the case with Bulgarian and Turkish yarn manufacturers.
However by looking at the meterage,and recommended needle size in this yarn weight chart, which are also given on the ball band, it is possible to determine the weight of any given yarn.
Another useful method of determining weight is by, wraps per inch, or wpi. To do this wrap the yarn around a large needle or a ruler. Make sure that the yarn lies flat and push the yarn together so that there are no gaps between the wraps. Smooth it out so it is neither too loose nor too tight then measure the number of wraps per inch (2.5 cm). For better accuracy, measure the wraps at the center of your yarn sample.
The number of wraps will act as a gauge to assess the thickness of unmarked yarn; for example 12 wraps per inch is 12 wpi, and is used to calculate how much yarn is required for various articles,so that 12 wpi is equivalent to DK,8 ply (worsted weight, medium weight) yarn.
Below is a table comparing yarn weights (ply or thicknesses) in a range of countries
|USA||South Africa / UK||Australia||Germany||m/100g||Wraps Per Inch||Recommended knitting needle size, mm||Recommended crochet hook size, mm||Other terms used|
|0 or Lace||1 ply||More than 800||40+ wpi||1.5 - 2.5||1.5 - 2.5||Single, Cobweb, Thread, Zephyr|
|0 or Lace||2 ply||2 fädig (ply)||600-800||30-40 wpi||1.5 - 2.5||1.5 - 2.5|
|1 or Super Fine||3 ply||3 ply||3 fädig||500-600||20-30 wpi||2 - 3||2.25 - 3.5||Light Fingering, Sock, Baby|
|1 or Super Fine||4 ply||4 ply||4 fädig||350-450||14-24 wpi||2 - 3||2.25 - 3.5||Fingering, Sock, Baby|
|2 or Fine||5 ply||6 fädig||250-350||12-18 wpi||3 - 4||3.5 - 4.5||Sport, Baby, 3-ply (obsolete American)|
|3 or Light||DK (Double Knit) or 8 ply||8 ply||200-250||11-15 wpi||4 - 4.5||4.5 - 5.5||Light Worsted, DK|
|4 or Medium||Worsted, Aran, Triple Knit (rare)||10 or 12 ply||120-200||9-12 wpi||4.5 - 5.5||5.5 - 6.5||Worsted, Afghan, Fisherman, 4-ply (obsolete American)|
|5 or Bulky||Chunky, Double Double Knit (rare)||12 or 16 ply||100-130||6-8 wpi||5.5 - 8||6.5 - 9||Craft, Rug|
|6 or Super Bulky||Super Chunky, Seriously Chunky||Less than 100||5-6 wpi||>8||>9||Roving|
|7 or Jumbo||Less than 100||n/a||12.75 mm and larger||15 mm and larger||Roving|
Types of yarn weights:-
0 - LACE (1 or 2 ply)
Yarns: fingering, thread
Used to make: Doilies or other delicate projects.
1 - SUPER FINE (3 or 4 ply)
Yarns: sock, fingering and baby
Used to make: baby items, socks, airy shawls and wraps.
2 - FINE
Yarn: sport and baby
Used to make: baby items, lightweight throws.
3 - LIGHT (Double Knit)
Yarns: DK, light worsted
Used to make: baby clothes, socks and other
4 - MEDIUM (Aran)
Yarns: worsted, afghan, aran
Used to make: practically anything — this is the
most common yarn weight. If you're a beginner,
it's a great weight to practice your stitches with.
5 - BULKY (Chunky)
Yarn: rug yarn, chunky, craft
Used to make: home decor, bulky winter items
like hats and scarves.
6 - SUPER BULKY (Seriously Chunky)
Used to make: heavy scarves, hats, home decor items or anything else you would like to knit up quickly.